Toast the cumin seeds in a pan until fragrant and then crush in a pestle & mortar until powdered.
In a medium-size saucepan add the lentils, chopped tomatoes and turmeric, then cover with the stock and stir together. Bring up to the boil, then reduce the heat to low, cover and simmer gently for 25–30 minutes, stirring occasionally until the lentils are tender. Remove from the heat and set aside.
Put the oil in a large non-stick frying pan set over a medium-high heat.
When hot add the onions and cumin seeds and fry for 5 minutes until soft and golden, then add the green chilli, garlic, chilli flakes and fry for 30 seconds until everything becomes fragrant.
Turn the heat up to medium, then take the lentils and carefully ladle them into the pan. Add the butter and fresh spinach and stir until everything is fully mixed. Bring up to the boil and season. Remove from the heat and garnish with coriander to serve.
To make the pancakes, place the flour and salt in a bowl and mix together then add the fizzy water until you have a smooth batter that’s not too thin. Stir through the chopped coriander.
Heat a crepe pan over a medium heat and grease with a little oil. Spoon in enough batter to cover the bottom of the pan and cook until the top of the pancake begins to look dry. Flip over and cook on the side until golden and then serve with the dal to mop everything up.